Radiator



M. G. STEELE Dec. 19, 1933.

RADIATOR Filed July 184, 1931 3 Shets-Sheet 1 j His ATTORNEYS M, G.STEELE Dec. 19, 1933.

RADIATOR Filed July 18, '1951 SSheets-Sheefc 2- Hi5 ATTORNEYS l Givin/34 3 Sheets-Sheet 5 RADIATOR M. G. STEELE Filed July 18, 1931 l I I 1If i Dec. 19, 1933.

j i I l INVENTOR fl/AWfi/(f 6, 522225 HISATTORNEYS UNITED STATES PATENTOFFICE RADIATOR Maurice G. Steele, Rome, N. Y., aasignor to RevereCopper and Brass Incorporated Application July 18, 1931. Serial No.551,651

17 Claims.

This invention relates to heat-exchange apparatus and has for its objectcertain improvements in the construction of heat-exchange devices. Theinvention relates more particularly to radiators, in which a heatingfluid, such as steam or hot water, is passed through a conduit made ofmetal of high heat-conductivity and on which are mounted a plurality ofspaced heat-dissipating fins, which transfer the heat from the fluid tothe air surrounding theradiator.

Various proposals have been heretofore advanced in the construction ofso-called fin-type radiators. that radiators of this type now availableare often deficient in their capacity to extract heat from the heatingfluid employed, in lightness, in compactness, and freedom frommechanical tlifliculties, and in flexibility in use.

The present invention contemplates important improvements in theconstruction of heat-exchange apparatus, such as radiators of the fintype. A highly eflicient extraction of heat from the fluid employed maybe obtained; the radiator is light, compact, and substantially free frommechanical difliculties. The radiator is, moreover, so designed as togive considerable flexibility in its use.

An important feature of the present invention is the arrangement ofnovel side plates extending between the headers in conjunction with theflns mounted on the tubes extending between the headers. These platesare adapted materially to diminish the amount of heat dissipated in theform of radiant heat energy, and, hence, appreciably to increase theamount of heat dissipated by convection. The side plates are alsoadapted to give rigidity to the assembly, and thus prevent the tubesfrom sagging; while at the same time offering important protection tothe fins against bending and permanent deformation.

Important improvements are also contemplated in the headers employ'ed.They are provided with strategically placed reservoirs or r pockets forthe accumulation of grit, scale, and foreign metal particles. Suitableprovision may be made in conjunction with these pockets for periodicallyremoving accumulated dirt. The headers, moreover, may be adjusted inheight to give the radiator proper pitch for the ready flow ofcondensate. A particular improvement contemplated is the provision inthe header of a multiple of suitably placed openings or tappings withwhich to make connections for the introduction of steam or for thewithdrawal of con- At the same time, it is recognized densate; therebygiving considerable flexibility in the installation of radiators.

Important improvements are also contemplated in the construction of theflns. They are designed to give considerable rigidity and resiliency,while at the same time offering greater surface area for the dissipationof heat than is normally the case. Their spaced relationship to oneanother is better preserved according to the practice of the invention.

The present invention is also directed to novel improvements in themanner in which the tubes are non-leakably attached to the headers bymeans of compression screws. The construction of the header and of thecompression screw are so inter-related that a flared end of the tubemay-be rigidly, uniformly and completely locked to provide a joint thatmay be subjected to considerable rough treatment without leaking.

According to another aspect of the invention, improvements arecontemplated in radiator unit assemblies involving the use of more thantwo (for example three) headers. Thus, in the use of three headers, theradiator units may be assembled so that heating fluid (such as steam) isso introduced into the central header and condensate is removed from theend headers; or, so that steam is introduced into the end headers andcondensate is removed from the central header. In a modifiedconstruction, the central header may act only as a support, in whichcase the condensate flows back to the end headers.

These and other features of the invention will undoubtedly be betterunderstood from the description which follows of certain embodiments,taken in connection with the accompanying drawings, in which:

Fig. 1 is a side elevation, in part sectional, of a radiator;

Fig. 2 is an end elevation with parts broken away of the radiator ofFig. 1;

Fig. 3 is a broken top plan view of the radiator of Fig. 1;

Fig. 4 is a detail section showing the manner of securing the ends ofthe tubes to the headers;

Fig. 5 is a plan view of one of the heat-radiating flns;

Fig. 6 is an end view of the fin of Fig. 5;

Fig. 7 is a side elevation, in part sectional, of another form ofradiator;

Fig. 8 is an end elevation of the radiator of i F1Fig. 9 is a top planview of the radiator of 8. 7; Fig. 10 is an enlarged perspective view ofthe improved heat-radiating fin shown in Figs. '7 and 9;

Fig. 11 is a side elevation of a multiple radiator in which steam is fedinto a central header and condensate is withdrawn from end headers;

Fig. 12 is a side elevation of a multiple radiator in which steam is fedinto end headers and condensate is withdrawn from a central header; and

Fig. 13 is a side elevation of a multiple radiator in which steam is fedinto end headers and condensate is withdrawn through the same endheaders.

Referring to the construction shown in Fig. 1 of the drawings, theradiator according to an embodiment of the invention is composed of apair of headers 1 united by a pair of horizontal tubes 2; although itwill be understood that any con-' venient number of tubes may be thusemployed. The headers consist of fiat, hollow castings, usually of castiron; although other metals such as brass, copper or aluminum may beused. These headers are generally rectangular in outline, and aresupported above the floor level upon vertical legs 3 screwed intoopposite sides of the headers so that by varying the distance to whichthe pairs of legs are screwed within their respective headers the tubes2 may be disposed at a slant so as to drain off any condensate formingin the tubes. A heating fluid such as steam is introduced into one ofthe headers, which may be termed the inlet header, through a conduit 4provided with a supply valve 5 for regulating the amount of the steamentering the radiator. Condensate is formed in the tubes 2, which aretilted at a slight angle downwardly toward the other header, which maybe termed the outlet header, and passes through an outlet conduit 6provided with a trap '7 for regulating the withdrawal of condensate fromthe radiator. In order to increase the heatconducting surface of theradiator the tubes 2 are provided with a multiplicity of fins 8 tightlyaffixed to the tubes. these fins, as in the case of the tubes, beingmade of copper or brass (although other metals may be employed, such asaluminum, steel, etc.) by reason of the improved heat-conductingproperty of these metals.

The inlet header 1 is provided on its bottom wall with an opening 9 bywhich the conduit 4 is threadedly connected with the header. A dirtpocket 9' is advantageously located at or near the bottom of theinterior of the headers for the collection of grit, metal particles andthe like; to prevent them from entering and obstructing the delicateoperation of the trap 7. A tapped opening at the top of the headerpermits the attachment of an air valve; or when such a valve is notused, this opening may be closed by a plug as shown in the drawings. Thetapped opening may also be adapted for connection with a source of fluidsupply. A tapping or screw-threaded port 10 in the end wall of theheader permits optional connection with a source of fluid supply; or toconnect a plurality of the radiators in series; otherwise this port isclosed by a suitable plug as shown. The plug is preferably of therecessed socket, or countersunk type, to give a flush construction.

The side walls of the headers are provided with holes 11, in the presentcase two in number, which provide passages through which the tubes 2communicate with the interior of the headers. Exteriorly of the headerand concentrically formed with reference to the holes 11 are recesses 12each provided on its bottom with a tapered seat 13 arranged to fitwithin and cooperate with one of the flared ends of the tube (Fig. 4).The interior of the recess at its outer end is screwthreaded, andloosely surrounding the tube and engaging the screw threads of therecess is a compression screw 14.

The compression screw has its inner end com plementarily beveled as at13 to conform to the taper of the inner side of the flared end of thetube, so that when the compression screw is turned home its beveled edgeengages the flared end 2 of the tube and forces it into fluidtightengagement with the tapered seat 13. The joint is capable ofwithstanding high internal pressures and is not easily loosened byrepeated expansion and contraction of the tube. The outlet header at theopposite end of the radiator is of substantially the same constructionand requires no discussion, equivalent elements being designated by thesame reference numerals. In flaring the ends of the tubes the flaredmetal is stretched and expanded. This means that the metal lip is madegradually thinner toward its extreme end. To compensate for this varyingthickness of the metal lip, the tapered seats 13 and 13' are pitched atan appropriate angle so that the entire lip is tightly, uniformly andcompletely engaged between the tapered seats. Thus, I have determinedthat when the seat 13 of the compression screw is given an 82 bevel, theseat 13 of the header should be given a bevel when using a tube having awall thickness of 0.035 of an inch.

The core section, comprising the tube and fin assembly, is constructedas follows: The tubes 2, as has before been stated, extend between thespaced headers l and deliver the heating fluid from the inlet header tothe outlet header; and in order to increase the heat-transferencecapacity of the tubes a series of fins 8 are arranged upon the tubes.These fins, as shown in Fig. 5, comprise thin metal plates ofrectangular shape and formed with two holes through which the tubespass. These holes are punched out in such a manner as to leave a shortlip or burr 8a surrounding the apertures, this lip affording a narrowcircumferential band of metal which firmly grips the circumferentialouter surface of the tubes. The tubes and the fins are preferably bondedtogether, such as by a solder joint, to obtain optimum heat conduction.

Upon its two opposite sides the radiator is skirted by a pair ofvertical walls 15. These walls not only protect the fins, add strengthand rigidity to the assembly, and contribute to the neat appearance ofthe radiator unit, but serve, in conjunction with the fins, the purposeof creating at least a partial flue effectthat is, inducing acirculation of air from below the radiator up between the walls 15 pastthe radiating fins 8, the heated air passing out above the radiator. Thewalls 15 are rigidly assembled with the radiator in one embodiment ofthe invention by means of tongues 16 punched out of their sides and bentinwardly. These tongues are perforated as at 1'? to encircle the tubes 2with which they are rigidly united in the same manner as the fins. Theseside plates prevent sagging of the tubes, which sagging might otherwisetrap condensate and seriously impair the heat-exchange efficiency of theassembly. The corners of the fins are protected against being pushed andbent together, whereby their spacing is better preserved.

The headers 1 are rabbeted as at 18 snugly to receive the ends of thewalls 15 which lie flush with the corresponding surfaces of the casting.

Such an arrangement adds to the beauty of the assembly and preventsexposure of sharp edges with which those handling the device mightotherwise cut and scratch themselves.

While the escape of condensate through trap 7 is shown in the abovedescribed device, it will be clear that a different practice may befollowed.

Thus, the radiator may be inclined downwardly toward the inlet header,in which case condensate will flow through the tubes into the inletheader. Suitable provision should then be made for the escape ofentrapped air, which may be accomplished by placing an air valvepreferably in the top of the far header.

The heat-exchange device, or radiator, may take a form such as thatillustrated in Figs. 7, 8, 9 and 10. This construction is similar tothat of the radiator shown in Figs. 1 to 6, inclusive, except forcertain noveldifferences in the end headers, the heat-dissipating finsand the side walls- Referring to Fig. 7, it will be seen that theconstruction contemplated comprises integral headers 20 elongated in avertical direction so that one end rests directly upon the floor; orclose thereto by means of pitch adjusting screws 21, which areadvantageously arranged with their heads at the bottom for ready access.This header construction permits of a relatively large interior chamber22, communication to which is permitted by a plurality of tappings oropenings strategically placed and spaced in opposite side walls, as wellas in the top wall. Thus, holes 23 and 24 are advantageously provided inopposite walls of the header at a convenient distance above the bottomof the chamber 22. In the instant construction the conduit 4 provides aninlet for steam through hole 24 into the chamber 22, by way of theinside side of the radiator. When not in use, the hole 23 is closed bymeans of a suitable plug 25. This plug is preferably 01 the countersunktype, so that it may be brought flush with the side walls of the header.Depending on local conditions, it will be clear that in someinstallations it may be preferable to connect the conduit with theheader by means of the hole 23; in which case the hole 24 would besuitably plugged. An extra upper side hole 10 and atop hole 10' areshown for similar connections; these holes being plugged when not inuse.

In order to provide a reservoir or space for' the collection of grit andforeign particles, openings 23 and 24 are made to communicate with thechamber 22 a convenient distance above its bottom. Thus, the bottomportion 26 of the chamber may be utilized as a dirt pocket or sump forthe collection of foreign impurities. The header may well be constructedso that the sump extends close to its bottom. A clean-out plug 26advantageously fits into a hole located at or near the bottom of thesump so that accumulated dirt may periodically be withdrawn from thesystem.

The side of the upper end of theheader 20 is advantageously constructedin accordance with the form shown for header 1 in the radiator ofFig. 1. The tubes 2 are attached in a similar manner by means ofcompression screws.

Instead of employing strictly flat heat-dissipating fins, as moreparticularly shown in the radiator of Figs. 1 and 3, fins 27 of theradiator of Figs. 7 and 9 are formed in accordance with the design ofFig. 10. These fins are provided with suitably spaced holes 28 for theinsertion of the tubes 2. The holes are appropriately 1 broached toprovide burrs or shoulders 29 for fitting around and against the tubes.In the construction shown, suitably spaced vertical corrugation s,grooves or channels 30, 31, 32 and 33 are provided across the width oithe fins. Corrugated fins are more rigid and resilient than they wouldbe in the absence of corrugations. Due to the added surface provided bythese depressions, the fins offer greater heat-dissipating surface. Aswill be more clearly shown by referring to Fig. 9, the corrugations tendto maintain the fins in spaced relationship to, one another. Should anyof the fins be bent toward one another, these corrugations give the finsgreater resiliency, or snap, which will tend to bring the fins back totheir original position. In order to make the placement of the fins onthe tubes easier, the grooves should be suitably spaced away from theholes 29, as shown. The ends of the fins are given greater strength byvirtue of the grooves 30 and 33 along or near the end edges.

Since the fins employed in this type of radiator are extremely thin, itis highly important that adequate provision be made to protect themagainst bending so that their spaced relationship to one another may bemaintained. The heatdissipation efiiciency of the radiator is also inlarge part dependent upon the maintenance of the spaced relationship ofthe fins. Passageways for the free movement of air are provided betweenadjacent "fins. In the construction shown a light force may be employedto bend the fins toward one another, but when that force is released,the fins promptly spring back to their normal position. This highlydesired resiliency or snap is given to the fins by the corrugations. Thecorrugation of the fins is also highly desirable in order to take out aslight curvature that is normally present when the fins are first cutfrom stock material. The stock material usually comes in the form of aroll or spool of thin copper or brass sheeting. The metal sheeting'isunrolled and cut into standard fin sizes. In the absence of suchcorrugations, the fin blanks would normally assume a slightly curvedform. On corrugating these slightly curved fin blanks, they assume andmaintain a substantially fiat shape.

Unlike the side walls of the radiator of Figs. 1, 2 and 3, side walls 34of the radiator of Figs. 7, 8 and 9 are in the form of a channel, theirupper and lower edges being flanged over preferably in amount sufiicientto cover and protect the corners of the fins. In the instantconstruction, the side walls or side plates are pulled against theheadersby means of bolts 35 extending from one side plate to the other;the'bolts extending through slotted holes in the plates spaced to makethem register oppositely to one another. This form of side plate offersa number of important advantages: Due to'the flanged edges, thechannel-like side walls are made extremely rigid. This construction notonly prevents sagging and side-bending of the walls, but it alsoprevents sagging of the tubes 2. Since the tubes are made of relativelythin metal they tend to sag when suspended between headers placed toofar apart, and when too many fins are attached to the tubes. Theundermost flanges of the side walls are adapted to extend slightly underthe fins. Hence, when any sagging tends to take place, the core assemblyof tubes and fins is supported by those flanged portions.

Even though every sixth or seventh fin, for exof the tubes is inherentlydisadvantageous in at least several important respects: In the firstplace, when the tubes sag at their centers, condensate is trapped in thebottommost portion. The collection of condensate at this point may tendto clog the tubes with water, and thus prevent the passage of steamthrough the tubes. Furthermore, when the tubes sag, the upper ends ofthe fins tend to close-in toward one another, thus inhibiting the freepassage of air upwardly through the spaces normally provided betweenadjacent fins.

In the construction shown in Fig. '7, the radiator is tilted at a veryslight angle so that condensate formed in the tubes 2 may fiow bygravity toward the opposite or outlet header, and from the header intothe trap 7. It will be clear that the trap may be omitted, in which casethe radiator is tilted in the opposite direction so that condensate mayfreely flow toward the steam inlet header. In this case an air valveshould be attached to the top of the far header for the escape ofentrapped air.

The present invention also contemplates the type of radiatorconstruction shown in Figs. 11, 12 and 13 in which more than two headersare employed; for example, three headers. When employing three headers,the intermediate header may be employed either as an inlet header forsteam (as in Fig. 11) or as an outlet header for the escape ofcondensate and entrapped air (as in Fig. 12) or as a mere support (as inFig. 13), in which case fresh steam is not introduced through the headernor is condensate removed therethrough. ,In the case of the radiatorconstruetion shown in Fig. 11, the steam enters a central header 36, andcondensate fiows to the end headers 3'7. In the construction shown inFig. 12, steam is introduced into end headers 38, and condensate andentrapped air are withdrawn through central header 39. In theconstruction of Fig. 13, the steam is likewise introduced into the endheaders 38 and the condensate flows backwardly into the same headers;the intermediate header 40 being employed primarily as a centralsupport. In this construction an air valve 41 is preferably attached tothe top of the central header for the escape of entrapped air. The tubesbetween adjacent headers may be suitably inclined to get the desiredflow of condensate, by suitably adjusting the height of the headersrelatively to one another. In the radiator of Fig. 11, the centralheader is elevated slightly higher than the two end headers; of Fig. 12the end headers are elevated slightly higher than the central header;and of Fig. 13, the central header (like Fig. 11) is slightly higherthan the two end headers.

While the invention has been described in connection with a steamradiator, manifestly heating mediums other than steam may be employed,such, for example, as vapor or hot water. Furthermore, variations in thesize, shape and number of fins and heater tubes may obviously be madewithout departing from the present invention. The apparatus hereincontemplated may likewise be employed as a cooling device, in which casethe tubular members may contain the cooling fluid, such as cold water,brine or various other familiar cooling mediums known to this art.

I claim:

1. In a heat-exchange apparatus, the combination comprising at least onefluid conducting tube connected at eachend with a header, a connectionin one of the headers for the introduction of a heating fluid, aplurality of spaced heat-dissipating fins mounted on and bonded to thetube, and vertical side plates extending between the headers adjacent toand in part supporting the tube and fin core by means of flanged loweredges of the plates that extend partly under the fins and on which atleast one of the fins may rest to prevent sagging of the tube and fincore thereof whereby the fins are maintained in their normal spacedrelationship and condensate cannot collect in the tube, said side platesbeing held in free spaced relationship exteriorly of the tube and fincore and header assembly by means of a securing member extendinglaterally there between at a suitable point between the headers wherebythe tube and fin core and the header assembly may expand and contractindependently of the side plates and thereby prevent the apparatus frombeing twisted out of shape.

2. A heat-exchange apparatus according to claim 1, in which the headeris provided with a dirt pocket above the connection for the introductionof a heating fluid for the accumulation of foreign particles.

3. A heat-exchange apparatus according to claim 1, in which the headeris provided with an elongated interior chamber, the bottom of thechamber extending well below the connection for the introduction ofsteam or for the withdrawal of condensate, said bottom of the chamberproviding a sump for the accumulation of foreign substances.

4. A heat-exchange apparatus according to claim 1, in which the headeris provided with a sump for the deposit of dirt, said sump being locatedabove the connection for the introduction of a heating fluid, an openingbeing provided through the header wall into the sump for periodiccleansing thereof.

5. A heat-exchange apparatus according to claim 1, in which the verticalside plates support the tube by means of lugs running from the plates tothe tube.

6. A heat-exchange apparatus according to claim 1, in which the fins arevertically corrugated along their vertical edges.

7. In a heat-exchange apparatus the combination comprising tube endsflared to fit over beveled seats in headers, and beveled seats ofcompression screws fitting loosely around the tube which are tightly,uniformly and completely screwed against the flared ends of the tube tomake a non-leakable joint, the respective beveled seats of the headersand the compression screw being complementarily pitched to conform tothe graduated thickness of the flared end of the tube.

8. A heat-exchange apparatus according to 1 claim 1, in which aconnection is provided in the opposite header for the withdrawal ofcondensate and entrapped air.

9. In a multiple heat-exchange apparatus, the combination comprising apair of end headers and an intermediate header disposed between the endheaders, tubes connecting the intermediate header with the end headers,a series of heat-dissipating fins mounted on the tubes and vertical sideplates extending between the headers adjacent to and in part supportingthe tube and fin core to prevent sagging thereof whereby the fins aremaintained in their normal spaced relationship and condensate cannotcollect in the tubes.

10. A multiple heat-exchange apparatus according to claim 9, in which aconnection is provided for introducing a heating fluid into theintermediate header.

11. A multiple heat-exchange apparatus according to claim 9, in whichconnections are provided for introducing a heating fluid into the endheaders.

12. A multiple heat-exchange apparatus according to claim 9, in whichconnections are provided for introducing a heating fluid into the endheaders, connections being likewise provided in the end headers for thewithdrawal of condensate.

13. A multiple heat-exchange apparatus according to claim 9, in whichconnections are provided for introducing a heating fluid into the endheaders, a connection being likewise provided in the intermediate headerfor the withdrawal of condensate.

14. A multiple heat-exchange apparatus according to claim 9, in whichconnections are provided for introducing a heating fluid into the endheaders, a connection being providedin the intermediate header for theescape of entrapped air, said intermediate header being slightlyelevated with respect to the end headers so that condensate may flowfreely through the tubes to the end headers.

15. A multiple heat-exchange apparatus according to claim 9, in whichthe headers are provided with a sump for the accumulation of foreignsubstances.

16. In a heat-exchange apparatus, the combination comprising an integralheader provided with a plurality of tappings adapted for makingconnections with a source of fluid supply or with a drain for thewithdrawal of condensate, said tappings being located in opposite sidewalls of the header, and a sump at or near the bottom of the headerbelow the tappings for the accumulation of dirt.

17. In a heat-exchange apparatus, the combination comprising a header, aflared tube, and a compression screw, a tube end being flared to a lipof graduated thickness and fitting over a beveled seat provided in athreaded hole in the header, the compression screw fitting looselyaround the tube and having a beveled seat fitting on the flared lip, therespective beveled seats of the header and the compression screw beingcomplementarily pitched to conform to the graduated thickness of theflared tube lip whereby the lip may be tightly, uniformly and completelycompressed to make a non-leakable joint.

MAURICE G. STEELE.

